Robotic surgical systems have been used in minimally invasive medical procedures. During such a medical procedure, the robotic surgical system is controlled by a surgeon that interfaces with a user interface. The user interface allows the surgeon to manipulate an end effector that acts on a patient. The user interface has an input controller or handle that is moveable by the surgeon to control the robotic surgical system.
The end effectors of the robotic surgical system are positioned at the end of a surgical instrument that is connected to robotic arms. Each end effector can be manipulated by an Instrument Drive Unit (IDU). An IDU may have a drive motor associated with the end effector and be configured to move the end effector about a respective axis or to actuate a particular function of the end effector (e.g., approximate, pivot, etc. jaws of the end effector).
Safety systems in the robotic surgical system monitored the drive motor current. If the measured motor current exceeded a preset safety threshold a fault would be presumed and the motor would be turned off. These systems had limited ability to detect different types of faults as they did not take into account the actual forces at the motor output.
There is a need for robust instrument drive unit fault detection that is capable of identifying different types of faults beyond those associated with pure high current draw.